sunrpc: add a generic netlink family for cache upcalls

The auth.unix.ip and auth.unix.gid caches live in the sunrpc module, so they cannot use the nfsd generic netlink family. Create a new "sunrpc" generic netlink family with its own "exportd" multicast group to support cache upcall notifications for sunrpc-resident caches. Define a YAML spec (sunrpc_cache.yaml) with a cache-type enum (ip_map, unix_gid), a cache-notify multicast event, and the corresponding uapi header. Implement sunrpc_cache_notify() in cache.c, which checks for listeners on the exportd multicast group, builds and sends a SUNRPC_CMD_CACHE_NOTIFY message with the cache-type attribute. Register/unregister the sunrpc_nl_family in init_sunrpc() and cleanup_sunrpc().

Jeff Layton committed 7 months ago

Commit af81cb21 parent c13ecd48 files · +188 −1Browse files

Unified · Split

8 files

Documentation/netlink/specs/sunrpc_cache.yaml +40 −0
include/linux/sunrpc/cache.h +2 −0
include/uapi/linux/sunrpc_netlink.h +35 −0
net/sunrpc/Makefile +1 −1
net/sunrpc/cache.c +44 −0
net/sunrpc/netlink.c +34 −0
net/sunrpc/netlink.h +22 −0
net/sunrpc/sunrpc_syms.c +10 −0

Documentation/netlink/specs/sunrpc_cache.yaml+40−0

@@ -0,0 +1,40 @@
	1	+# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
	2	+---
	3	+name: sunrpc
	4	+protocol: genetlink
	5	+uapi-header: linux/sunrpc_netlink.h
	6	+
	7	+doc: SUNRPC cache upcall support over generic netlink.
	8	+
	9	+definitions:
	10	+ -
	11	+ type: flags
	12	+ name: cache-type
	13	+ entries: [ip_map, unix_gid]
	14	+
	15	+attribute-sets:
	16	+ -
	17	+ name: cache-notify
	18	+ attributes:
	19	+ -
	20	+ name: cache-type
	21	+ type: u32
	22	+ enum: cache-type
	23	+
	24	+operations:
	25	+ list:
	26	+ -
	27	+ name: cache-notify
	28	+ doc: Notification that there are cache requests that need servicing
	29	+ attribute-set: cache-notify
	30	+ mcgrp: exportd
	31	+ event:
	32	+ attributes:
	33	+ - cache-type
	34	+
	35	+mcast-groups:
	36	+ list:
	37	+ -
	38	+ name: none
	39	+ -
	40	+ name: exportd

include/linux/sunrpc/cache.h+2−0

@@ -256,6 +256,8 @@ int sunrpc_cache_requests_snapshot(struct cache_detail *cd, · 255 unmodified lines
256	256	struct cache_head **items,
257	257	u64 *seqnos, int max,
258	258	u64 min_seqno);
	259	+int sunrpc_cache_notify(struct cache_detail cd, struct cache_head h,
	260	+ u32 cache_type);
259	261
260	262	/* Must store cache_detail in seq_file->private if using next three functions */
261	263	extern void cache_seq_start_rcu(struct seq_file file, loff_t *pos);

include/uapi/linux/sunrpc_netlink.h+35−0

@@ -0,0 +1,35 @@
	1	+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
	2	+/* Do not edit directly, auto-generated from: */
	3	+/* Documentation/netlink/specs/sunrpc_cache.yaml */
	4	+/* YNL-GEN uapi header */
	5	+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
	6	+
	7	+#ifndef _UAPI_LINUX_SUNRPC_NETLINK_H
	8	+#define _UAPI_LINUX_SUNRPC_NETLINK_H
	9	+
	10	+#define SUNRPC_FAMILY_NAME "sunrpc"
	11	+#define SUNRPC_FAMILY_VERSION 1
	12	+
	13	+enum sunrpc_cache_type {
	14	+ SUNRPC_CACHE_TYPE_IP_MAP = 1,
	15	+ SUNRPC_CACHE_TYPE_UNIX_GID = 2,
	16	+};
	17	+
	18	+enum {
	19	+ SUNRPC_A_CACHE_NOTIFY_CACHE_TYPE = 1,
	20	+
	21	+ __SUNRPC_A_CACHE_NOTIFY_MAX,
	22	+ SUNRPC_A_CACHE_NOTIFY_MAX = (__SUNRPC_A_CACHE_NOTIFY_MAX - 1)
	23	+};
	24	+
	25	+enum {
	26	+ SUNRPC_CMD_CACHE_NOTIFY = 1,
	27	+
	28	+ __SUNRPC_CMD_MAX,
	29	+ SUNRPC_CMD_MAX = (__SUNRPC_CMD_MAX - 1)
	30	+};
	31	+
	32	+#define SUNRPC_MCGRP_NONE "none"
	33	+#define SUNRPC_MCGRP_EXPORTD "exportd"
	34	+
	35	+#endif /* _UAPI_LINUX_SUNRPC_NETLINK_H */

net/sunrpc/Makefile+1−1

@@ -14,7 +14,7 @@ sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \ · 13 unmodified lines
14	14	addr.o rpcb_clnt.o timer.o xdr.o \
15	15	sunrpc_syms.o cache.o rpc_pipe.o sysfs.o \
16	16	svc_xprt.o \
17		− xprtmultipath.o
	17	+ xprtmultipath.o netlink.o
18	18	sunrpc-$(CONFIG_SUNRPC_DEBUG) += debugfs.o
19	19	sunrpc-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel_rqst.o
20	20	sunrpc-$(CONFIG_PROC_FS) += stats.o

net/sunrpc/cache.c+44−0

@@ -33,9 +33,11 @@ · 32 unmodified lines
33	33	#include <linux/sunrpc/cache.h>
34	34	#include <linux/sunrpc/stats.h>
35	35	#include <linux/sunrpc/rpc_pipe_fs.h>
	36	+#include <net/genetlink.h>
36	37	#include <trace/events/sunrpc.h>
37	38
38	39	#include "netns.h"
	40	+#include "netlink.h"
39	41	#include "fail.h"
40	42
41	43	#define RPCDBG_FACILITY RPCDBG_CACHE
@@ -1963,3 +1965,45 @@ int sunrpc_cache_requests_snapshot(struct cache_detail *cd, · 1921 unmodified lines
1963	1965	return i;
1964	1966	}
1965	1967	EXPORT_SYMBOL_GPL(sunrpc_cache_requests_snapshot);
	1968	+
	1969	+/**
	1970	+ * sunrpc_cache_notify - send a netlink notification for a cache event
	1971	+ * @cd: cache_detail for the cache
	1972	+ * @h: cache_head entry (unused, reserved for future use)
	1973	+ * @cache_type: cache type identifier (e.g. SUNRPC_CACHE_TYPE_UNIX_GID)
	1974	+ *
	1975	+ * Sends a SUNRPC_CMD_CACHE_NOTIFY multicast message on the "exportd"
	1976	+ * group if any listeners are present. Returns 0 on success or a
	1977	+ * negative errno.
	1978	+ */
	1979	+int sunrpc_cache_notify(struct cache_detail cd, struct cache_head h,
	1980	+ u32 cache_type)
	1981	+{
	1982	+ struct genlmsghdr *hdr;
	1983	+ struct sk_buff *msg;
	1984	+
	1985	+ if (!genl_has_listeners(&sunrpc_nl_family, cd->net,
	1986	+ SUNRPC_NLGRP_EXPORTD))
	1987	+ return -ENOLINK;
	1988	+
	1989	+ msg = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
	1990	+ if (!msg)
	1991	+ return -ENOMEM;
	1992	+
	1993	+ hdr = genlmsg_put(msg, 0, 0, &sunrpc_nl_family, 0,
	1994	+ SUNRPC_CMD_CACHE_NOTIFY);
	1995	+ if (!hdr) {
	1996	+ nlmsg_free(msg);
	1997	+ return -ENOMEM;
	1998	+ }
	1999	+
	2000	+ if (nla_put_u32(msg, SUNRPC_A_CACHE_NOTIFY_CACHE_TYPE, cache_type)) {
	2001	+ nlmsg_free(msg);
	2002	+ return -ENOMEM;
	2003	+ }
	2004	+
	2005	+ genlmsg_end(msg, hdr);
	2006	+ return genlmsg_multicast_netns(&sunrpc_nl_family, cd->net, msg, 0,
	2007	+ SUNRPC_NLGRP_EXPORTD, GFP_KERNEL);
	2008	+}
	2009	+EXPORT_SYMBOL_GPL(sunrpc_cache_notify);

net/sunrpc/netlink.c+34−0

@@ -0,0 +1,34 @@
	1	+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
	2	+/* Do not edit directly, auto-generated from: */
	3	+/* Documentation/netlink/specs/sunrpc_cache.yaml */
	4	+/* YNL-GEN kernel source */
	5	+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
	6	+
	7	+#include <net/netlink.h>
	8	+#include <net/genetlink.h>
	9	+#include <linux/sunrpc/cache.h>
	10	+
	11	+#include "netlink.h"
	12	+
	13	+#include <uapi/linux/sunrpc_netlink.h>
	14	+
	15	+/* Ops table for sunrpc */
	16	+static const struct genl_split_ops sunrpc_nl_ops[] = {
	17	+};
	18	+
	19	+static const struct genl_multicast_group sunrpc_nl_mcgrps[] = {
	20	+ [SUNRPC_NLGRP_NONE] = { "none", },
	21	+ [SUNRPC_NLGRP_EXPORTD] = { "exportd", },
	22	+};
	23	+
	24	+struct genl_family sunrpc_nl_family __ro_after_init = {
	25	+ .name = SUNRPC_FAMILY_NAME,
	26	+ .version = SUNRPC_FAMILY_VERSION,
	27	+ .netnsok = true,
	28	+ .parallel_ops = true,
	29	+ .module = THIS_MODULE,
	30	+ .split_ops = sunrpc_nl_ops,
	31	+ .n_split_ops = ARRAY_SIZE(sunrpc_nl_ops),
	32	+ .mcgrps = sunrpc_nl_mcgrps,
	33	+ .n_mcgrps = ARRAY_SIZE(sunrpc_nl_mcgrps),
	34	+};

net/sunrpc/netlink.h+22−0

@@ -0,0 +1,22 @@
	1	+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
	2	+/* Do not edit directly, auto-generated from: */
	3	+/* Documentation/netlink/specs/sunrpc_cache.yaml */
	4	+/* YNL-GEN kernel header */
	5	+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
	6	+
	7	+#ifndef _LINUX_SUNRPC_GEN_H
	8	+#define _LINUX_SUNRPC_GEN_H
	9	+
	10	+#include <net/netlink.h>
	11	+#include <net/genetlink.h>
	12	+
	13	+#include <uapi/linux/sunrpc_netlink.h>
	14	+
	15	+enum {
	16	+ SUNRPC_NLGRP_NONE,
	17	+ SUNRPC_NLGRP_EXPORTD,
	18	+};
	19	+
	20	+extern struct genl_family sunrpc_nl_family;
	21	+
	22	+#endif /* _LINUX_SUNRPC_GEN_H */

net/sunrpc/sunrpc_syms.c+10−0

@@ -23,9 +23,12 @@ · 22 unmodified lines
23	23	#include <linux/sunrpc/rpc_pipe_fs.h>
24	24	#include <linux/sunrpc/xprtsock.h>
25	25
	26	+#include <net/genetlink.h>
	27	+
26	28	#include "sunrpc.h"
27	29	#include "sysfs.h"
28	30	#include "netns.h"
	31	+#include "netlink.h"
29	32
30	33	unsigned int sunrpc_net_id;
31	34	EXPORT_SYMBOL_GPL(sunrpc_net_id);
@@ -108,6 +111,10 @@ init_sunrpc(void) · 76 unmodified lines
108	111	if (err)
109	112	goto out5;
110	113
	114	+ err = genl_register_family(&sunrpc_nl_family);
	115	+ if (err)
	116	+ goto out6;
	117	+
111	118	sunrpc_debugfs_init();
112	119	#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
113	120	rpc_register_sysctl();
@@ -116,6 +123,8 @@ init_sunrpc(void) · 2 unmodified lines
116	123	init_socket_xprt(); /* clnt sock transport */
117	124	return 0;
118	125
	126	+out6:
	127	+ rpc_sysfs_exit();
119	128	out5:
120	129	unregister_rpc_pipefs();
121	130	out4:
@@ -131,6 +140,7 @@ out: · 9 unmodified lines
131	140	static void __exit
132	141	cleanup_sunrpc(void)
133	142	{
	143	+ genl_unregister_family(&sunrpc_nl_family);
134	144	rpc_sysfs_exit();
135	145	rpc_cleanup_clids();
136	146	xprt_cleanup_ids();